Currently, in order to improve the contrast between pixels and avoid reduction in the display quality due to light mixing between adjacent pixels, a latticed black film layer provided with BMs is disposed between pixels of a CF substrate.
In the conventional process of forming BMs, the method of forming patterns by depositing and etching chromium (Cr) as a pigment on the entire glass substrate is used. The forming process is complex and meanwhile has the problems such as high reflectance of the raw material Cr and environmental pollution due to easy production of Cr waste.
Therefore, the researchers have developed a method of dispersing black pigment (e.g., carbon black) in a resin layer and utilizing the light absorption characteristic of black pigment to achieve a light shielding effect. However, BMs formed by dispersing the black pigment in the resin layer still have the following defects:
Firstly, as the majority of black pigment (e.g., carbon black) has a larger particle size (typically in micron level) and has poor dispersivity in resin, solvent and the like, the film uniformity and the film forming adhesion of the BMs can be adversely affected.
Secondly, in order to ensure good light shielding effect of the BMs, the usage amount of the black pigment has to be greatly increased, so that the overall thickness of the resin layer can be larger, and hence the overall flatness of the CF substrate can be reduced, and consequently the display quality can be degraded.
In view of this, a novel light shielding material with a better light shielding performance and a smaller particle size is urgently needed by those skilled in the art.